British Patent Specification 1,225,956 discloses a process for the production of a chlorofluoroethane of the general formula CH.sub.3-n Cl.sub.n CClF.sub.2 where n is 0 to 3 comprising the photochemical chlorination of 1,1-difluoroethane, which may contain less than 2% HF.
Belgian Patent Publication BE 844,822 as cited in CA87(10): 68874q discloses the photochemical chlorination of 1,1-difluoroethane in the gas phase to afford 1-chloro-1,1-difluoroethane.
There has been considerable interest in processes for the chlorination of aliphatic hydrofluorocarbons and hydrochlorofluorocarbons which avoid using expensive actinic light to effect such chlorination.
U.S. Pat. No. 2,644,845 claims a non-catalytic process for the chlorination or bromination of a 1,1,1-trihaloethane or -propane at a reaction temperature of between about 365.degree. C. to 450.degree. C. The chlorination of 1,1,1-trifluoroethane (HCFC-143a) at 497.degree. C in 45% yield and with the following selectivities is shown in Example 6: 22% HCFC-133a, 33% HCFC-123 and 45% CF3CC13 (CFC-113a)
U.S. Pat. No. 4,490,534 discloses a process for the preparation of 3-chloro-5-trifluoromethylpyridine derivatives comprising reacting a 5-trifluoromethylpyridine having a hydrogen atom at the 3-position with chlorine in the presence of a catalyst selected from the group consisting of activated carbon and a chloride of a metal selected from the group consisting of iron, antimony, copper and zinc.
1,1,1-Trichloro-2,2,2-trifluoroethane (i.e., CFC-113a or CCl.sub.3 CF.sub.3) is a chlorofluorocarbon which has been used as an intermediate for the preparation of 1,1,1,2-tetrafluoroethane (i.e., HFC-134a or CF.sub.3 CH.sub.2 F). More particularly, 1,1,1-trichloro-2,2,2-trifluoroethane can be reacted with HF to afford 2,2-dichloro-1,1,1,2-tetrafluoroethane (i.e., CFC-114a or CF3CC12F) which can then be converted to HFC-134a by hydrogenolysis. There is thus interest in developing efficient methods of producing CCl.sub.3 CF.sub.3.